EAE - what to change and when

[sdtib]

I finally have my tune dialed in on my MS2 extra and I am ready to take a stab at EAE but I am not sure where to start. The old (archived) MS-3 web manuals have a small section on tuning EAE which I am sure will be very helpful. The final statement in this section reads "The following table explains what corrective actions to take depending on whether the engine goes lean or rich in specific situations:" but there is no table, can someone tell be if or where this table exists, it is not in the new manuals.

Thanks

[mrx79]

Can't tell you where the manual has gone, but i can mention my thread about EAE which i made a few weeks ago and where Alex came in and gave me some very good hints on EAE.

I tuned my EAE with that and got it working quite well in a week with two measurements and adjustements each day (trip from and to work).

If you read this and take a look at my log's i posted, i'am sure you will figure it out.
If not, post up some log's and MSQs here and i (and maybe Alex or a few others) will take a look and give you hints.

PS: the way Alex and i tuned it is a bit different from what the manual saied, but it's getting pretty good results.

Best regards

[sdtib]

Thanks for the reply.

I actually had already read that thread and downloaded your .msq. Your sucked from the walls curve has the reverse slope of the example that is in the manual. That is kind of confusing to me since I thought the curves, although different for every vehicle, should resemble the one's in the manual but I guess Alex covered that in your thread. I think sometimes they put weird stuff in the manuals just to make you have to figure it out for yourself.

I would still love to have some sort of a chart that says....

If tip in is lean then (increase/decrease) (???) value
If decel is rich then (increase/decrease) (???) value
etc.
etc.
etc.

Anybody have something like that????

[mrx79]

Yes, you are right Alex any myself did it the other way around like in the manual.
I had some luck with the way it was described in the manual as well, but not that much like this time when i followed Alexes way.

And think about it a second. What happens at high vacuum with the puddle?! there is more suction which increases the amount which is sucked from the walls.
Also if there is going much from the wall, it is clear that there can't be put too much to the wall.

This is key, you have to understand what's going on physicaly. Only if you understood this, you can realy improve EAE calibration.

There are some threads with a basic table of what to do, but as both parameters and curve shapes are influencing each other, together with the actual PW at a certain moment influences the amount of adhere-to-wall quantity and wallfuel behaviour, you realy have to understand what the algorithm is doing.

There is no simple, is it lean, do that... because if can be lean for several reasons.

But as a rough guideline:
I try to work on Adhere on positive load changes and of course, if it's lean i increase the adhere to wall factor.
And i try to work on SuckFromWall factor on negative load changes.

But when it comes to time constant tuning, it is the difference between the two which will make the deal.
Changing that, will also re-influence the amount, so it's a constant improvement.

It will take some time, but when you understood it, it's easy to decide what to do.

Go out, do some easy (not too fast, not too slow) load changes and see what it is doing. If you lean out totaly and have no clue, do slower load changes to see whats going on.
If you need more help, post a log and msq and we will take a look. Do small steps and only one thing at a time. Then we will sort it out.

[Perkele]

Sorry for stealing this tread but can someone point me to the right direction and perhaps take peek of my log?

I know how the basics of the EAE goes and I think I'm quite close but, I don't know how do change the duration of the EAE?
Because now it looks like there is too little EAE right after load change and it takes too long to get back to normal.

I know that the initial AFR spike needs to be tuned away later with normal AE, but does the first big AFR chage after load change seem a bit long, or is it normal?

The msq has normal AE on Deccell on but those were off when logging.

Thank you.

[mrx79]

Looks quite good. Your engine seems to need very little wallfuel.
The duration of EAE you can influence by increasing or decreasing the difference between the two curves.
the bigger the difference, the longer it takes to equalize the wallfuel formula which lead to longer EAE interventions.
the smaller the differente, the shorter the EAE intervention is.

But be aware, that shifting one curve up or down, also influences the amount of wallfuel.
It can be very tricky, so if you are pleased with driveability, i would not mess very much, or at least always know your last known good calibration.

Don't try to completely eliminate the negative load rich peaks, if you do, you will get a very high lean peak after that (i tried that).

Your Log looks good, if there is no driveability impact, just add a short burst of TPS ae and call it a day.
maybe try to finetune some static ranges, there seems a few areas where it can be improved a bit, but noting of a great deal.

PS: Can you post or send me a log of a cold start in the morning. I would like to see how your EAE intervention during start and afterstart (first few seconds) looks like.

Best regards

[Perkele]

Thanks for the info.

It actually behaves quite well so mayde I'll leave the EAE as it is and fine tune with AE.

I will make the log for you when I do my next cold start.

[Perkele]

Here's the log from the cold start.

As you can see it doesn't work that well when the intake is really cold.
At random load increases the AFR jumps very lean and it's definitely noticeable, luckily this behaviour goes away quite fast.

[Rick Finsta]

You can try tweaking your EAE's CLT tables...?